Device for removing eyelets, in particular stainless steel eyelets, from textile or plastics sheets.
Eyelets in textile or plastics sheets, for example in lorry tarpaulins, wear through in the course of their use and thus have, as a rule, a service life which is significantly less than the textile or plastics sheets. For this reason it is usual and economically worthwhile to replace the worn-through eyelets with new ones, in order thus to be able to exploit the total service life of the textile or plastics sheet.
From DE 36 33 539 A1 there is known a device for placing metal eyelets into the tarpaulins of lorries, or the like, which consists of a tool holding the eyelet upper part and a tool holding the eyelet lower part, whereby the two tools can be brought together in such a way that the tube-shaped neck of the eyelet upper part engages through the preperforated tarpaulin and its free edge is flanged around behind the inner edge of the ring-shaped eyelet lower part, the tool holding the eyelet lower part being arranged in the tool receiver of a hydraulic stamping cylinder and the tool holding the eyelet upper part being arranged in the tool receiver of an hydraulic flanging cylinder, and the two cylinders being connected with one another with an approximately semicircular yoke. Although it is proposed in this document to use the device also for the removal of eyelets, in that stamping tools are placed in the tool receivers of the two cylinders, with which stamping tools the inner edge of the metal eyelet is cut off, this configuration variant has not found favour. The reason for this can be understood to be that the device is relatively bulky and that the stamping off of the inner edge requires high pressures (higher pressures than the flanging), and leads to damage to the tarpaulin.
From DE 93 15 550.6 U1 there is known a tool for placing eyelets, in particular stainless steel eyelets, into textile or plastics sheets, which likewise is of a tool element holding the eyelet shaft part and, positioned opposite thereto in the usage disposition, a counter-element, holding the eyelet disc, with the interposition of the sheet, whereby there is provided for guiding the eyelet shaft part a centrally movable stamp, which slightly projects beyond the free edge contour of the eyelet shaft part, and an embossing stamp, surrounding the central stamp, movable relatively thereto, for embossing self-stamping eyelet shaft parts. This device is not suitable for the removal of eyelets.
From EP 0 655 205 A2, finally, there is known a press driven by a pressure medium, in particular an hydraulic eyelet press, for perforating sheets and emplacing edge reenforcing eyelets for the hole. This press consists of a cylinder housing with two pistons, nested within one another, of which one deals with the flanging operation and the other the hole stamping operation. Here also, no possibility for the removal of eyelets is provided, so that the removal of the eyelets must be effected manually.
It is thus found to be the case that in practice eyelets are still opened in a complicated manner by hand, which is uneconomic.
From DE 32 16 179 C2 there is known a device for releasing fixedly rivetted eyelets which reinforce the edge region of openings in a sheet. The device has on the one hand a stamp and on the other hand a stamp receiver which with their oppositely acting cutters separate an inner ring zone of the eyelet from an outer ring region of the eyelet. However, this solution has not found favour in practice.
It is thus the object of the invention to provide a device for the removal of eyelets, in particular stainless steel eyelets, from textile or plastics sheets, which is easy to handle and which is economic in manufacture.
The object is achieved in that there are provided means for pressing a beading of the eyelet in the direction of the eyelet middle point or in the opposite direction.
One configuration of the invention consists in that, as means for pressing the beading of the eyelet, there is provided a substantially cylindrical or oval claw head having claws that can be spread apart from one another and can be closed.
It is within the scope of the invention that the claw head is formed as a substantially cylindrical tube section and has a plurality of claws separated from one another by means of axial incisions, which claws are, in the non-operative condition, spread apart from one another, and which can be pressed together by means of pushing over a control cylinder, over at least a part of the claw head.
Thereby, it is advantageous that at least 8 claws are provided.
Another configuration of the invention consists in that the claw head consists of radial claws attached at the end of a cylindrical tube section in a jointed manner, which claws can be spread apart from another by means of drawing a cone arranged within the claws, and which can be pressed together by pushing over a control cylinder over at least a part of the claw head.
A further development of the invention consists in that the claw head can be connected with a carrier tube which is displaceable, by means of pressure medium, within a housing, towards its forward end, and in that a control cylinder is arranged around the carrier tube, which control cylinder can be carried along with the carrier tube upon displacement thereof, and in that the control cylinder is displaceable, by means of a pressure medium, with respect to the carrier tube located in an end position, further in the direction of the forward end of the housing, over at least a part of the claw head.
It can also be provided that the claw head is connectable with a carrier tube which, by means of pressure medium, is displaceable within a housing towards its forward end, and that a control cylinder is arranged around the carrier tube, which control cylinder can be carried along with the carrier tube upon displacement thereof, and that the control cylinder is displaceable, by means of a pressure medium, with respect of the carrier tube located in an end position, further in the direction of the forward end of the housing, over at least a part of the claw head, and that there is provided a displaceable cone arranged in the axial direction of the housing.
In accordance with the invention it is advantageous that an anvil part is connectable with the housing, onto which anvil part the eyelet to be released can be brought.
It is also expedient that the device has means for stamping holes in the textile or plastics sheets.
It likewise lies within the scope of the invention that the device has means for placing eyelets in the textile or plastics sheets.
Further, it is useful that for stamping of holes a stamp head can be connected with the carrier tube, and for the applying of eyelets, a rivetting head can be connected with the carrier tube.
Finally, it is advantageous if the anvil part has a magnet.
The advantages of the present invention lie in substance in that a device is provided with which eyelets can be opened with the application of relatively little force. Due to the relatively slight pressures of the pressure medium necessary therefor, the device can be constructed handily and thus can be manufactured economically. With the device, eyelets can be removed directly at the installed textile or plastics sheet. By means of the possibility to use a stamping head or a rivetting head instead of the claw head, there is provided a tool suitable for all activities required in connection with eyelets.